package d10;

import java.sql.*;

public class xl1 {
    public static void main(String[] args) throws SQLException{
        /**JDBC连接数据库
         * 1.加载 驱动
         * 2. 连接
         * 3. 表结构
         * 4. 预处理
         * 5. 结果
         * 6. 释放 连接
         */
        /**
         * （1） 加载
         * a. 根目录创建Lib文件夹
         *  b.将连接的jar包放入lid
         *  c. 点击 文件->项目结构->模块->依赖->+号->JAR或目录->选中mysql的jar包
         *  d.编写加载代码
         */
        Statement stmt = null;
        ResultSet rs = null;
        Connection conn = null;
        try{
            //1.注册数据库的驱动
            Class.forName ("com.mysql.cj.jdbc.Driver");
            //2.通过DriverManager获取数据库连接
            String url = "jdbc:mysql://localhost:3306/jdbc?serverTimezone=GMT%2B8&useSSL=false";
            String username = "root";
            String password = "123456";
            conn = DriverManager.getConnection(url, username, password);
            //3.通过Connection对象获取Statement对象
            stmt = conn.createStatement ();
            //4.使用Statement执行SQL语句。
            String sql = "select * from users";
            rs = stmt.executeQuery (sql);
            //5.操作ResultSet结果集
            System.out.println ("id  |   name |  password"
            + "|   email      |   birthday");
            while(rs.next()){
                int id = rs.getInt ("id");//通过列名获取指定字段的值
                String name = rs.getString("name");
                String psw = rs.getString("password");
                String email = rs.getString("email");
                Date birthday = rs.getDate ("birthday");
                System.out.println (id + "|" + name + "|" + email + "|" + psw + "|" + birthday);
            }
        }catch (ClassNotFoundException e){
            e.printStackTrace();
        } finally {
            //6.回收数据库资源
            if (rs != null){
                try{
                    rs.close();
                } catch (SQLException e){
                    e.printStackTrace();
                }
                rs = null;
            }
            if (stmt != null){
                try {
                    stmt.close();
                } catch (SQLException e){
                    e.printStackTrace();
                }
                stmt = null;
            }
            if (conn != null){
                try {
                    conn.close();
                }catch (SQLException e){
                    e.printStackTrace();
                }
                conn = null;
            }
        }
    }
}
